REST page 2 item 0 === page 1 item 99 when requesting 100 posts from a post type

[vialars]

in our case of a custom WP post type default REST API call

page 2 item 0 === page 1 item 99

when requesting 100 items per page.

(as of writing this.)

Demo:

​https://deananddavid.com/wp-json/wp/v2/catering_article?lang=de&orderby=menu_order&order=asc&_fields=acf,catering_category,featured_media,id,title&per_page=100&page=1

​https://deananddavid.com/wp-json/wp/v2/catering_article?lang=de&orderby=menu_order&order=asc&_fields=acf,catering_category,featured_media,id,title&per_page=100&page=2

This is no issue when requesting 99 items per page.

[vialars]

this issue appears to be not present as of now just before writing this.

But it has been. Thus a circumstance which contributes to something like this occurring exists / has existed at that time.

Please have a look when caring for this.

[antonvlasenko]

I cannot reproduce this issue on WordPress 6.4.3 or the latest trunk version (6.6-beta3-58440-src).

I created a custom post type, added 300 entries to it, and sent 2 REST API requests to query the first and second pages (100 entries each). The endpoint correctly paginated the custom post type entries.

Since this issue does not occur on either WordPress 6.4.3 or the latest trunk version, I believe it is not related to WordPress Core itself.

@vialars Could you please provide the steps to reproduce the issue on a clean WordPress installation? Unfortunately, I am unable to reproduce it.

[vialars]

Hello @antonvlasenko , I couldn't reproduce it anymore 3/11/24, see comment #1. However it did occur on 3/6/24 .

I have no further clue as what the contributing circumstances are.

I thank you very much for looking into this issue!

[antonvlasenko]

Thank you for the update, @vialars.

I attempted to reproduce the issue again today, focusing on the "orderby" attribute, but was unable to do so.

Given that the issue occurred previously but not now, it might be due to a third-party plugin on your WordPress site, which can sometimes cause intermittent issues. Another possibility is a database integrity violation, where JOIN operations might lead to data duplication. However, these are just assumptions. I don't know how your website is configured exactly.

If you discover steps to reproduce the issue or have any additional information that could help, please feel free to reopen the ticket.